Gilead Sciences is evaluating the future of a cancer drug acquired in a multibillion-dollar deal following a new setback the company reported late Thursday.
In a statement, Gilead said it paused enrollment in four mid-stage trials of the drug, known as magrolimab, in different types of solid tumors. The Food and Drug Administration subsequently ordered a partial hold on these trials. The suspension also applies to investigator-run tests of magrolimab, the company said.
Gilead didn’t specify why it stopped recruiting study participants. However, one week ago, the company disclosed a regimen involving magrolimab was associated with an increased risk of death in a late-stage trial in leukemia. Gilead ended that study, and the agency halted all other tests of magrolimab in blood cancers.
Gilead said it is “reviewing the benefit-risk of magrolimab across all ongoing trials and will provide an update on this assessment as soon as possible.”
The announcement is yet another disappointment for magrolimab, which Gilead acquired when it paid $5 billion for biotechnology company Forty Seven in 2020.
Gilead bought Forty Seven to bolster its oncology business amid a surge of industry interest in drugs like magrolimab, which block a mechanism cancer cells use to evade the immune system. Gilead viewed these drugs as a cornerstone for cancer drug combinations and pushed magrolimab into mid- and late-stage trials in leukemia and myelodysplastic syndrome as well as solid tumors.
Magrolimab has since faced myriad delays and trial stoppages over safety concerns. It failed Phase 3 trials in myelodysplastic syndrome and leukemia, proving ineffective in both cases.
Meanwhile, some pharmaceutical companies have backed away from the drug class, which are known as CD47 inhibitors. Pfizer still has one in Phase 2 testing that was acquired via its buyout of Trillium Therapeutics. Biotech ALX Oncology is also testing a CD47 drug in mid-stage studies.
Gilead’s struggles come as Wall Street scrutinizes the company’s business development strategy under CEO Daniel O’Day. Partnerships with biotechs Galapagos and Arcus Biosciences haven’t paid dividends, and a drug acquired in its $21 billion buyout of Immunomedics hasn’t performed as well as expected.
Earlier this week, the company paid $4.3 billion to acquire liver drug developer Cymabay Therapeutics.
The four studies Gilead paused are evaluating magrolimab in colorectal, breast, and head and neck cancers, as well as in solid tumors more broadly. Patients who benefit from treatment can continue to receive the drug after again given their consent, the company said.